Question

The reaction shown is: \[ \text{Phenol} + \text{CHCl}_3 + \text{NaOH} \rightarrow \text{Salicylaldehyde} \] What is the name of the above reaction?

• A. Aldol condensation
• B. Reimer-Tiemann reaction
• C. Friedel-Crafts reaction
• D. Kolbe-Schmidt reaction

Hint:

The Reimer-Tiemann reaction is specifically used for the ortho-formylation of phenols. It is an important reaction in organic synthesis.

Answer 1

The Correct Option is B

This reaction involves phenol, chloroform (\( \text{CHCl}_3 \)), and sodium hydroxide (\( \text{NaOH} \)) to form salicylaldehyde, which is an example of the Reimer-Tiemann reaction.

1. Step 1: Understand the Reimer-Tiemann reaction. - The Reimer-Tiemann reaction is used to introduce a formyl group (–CHO) onto the benzene ring of phenols, typically using chloroform and a strong base like sodium hydroxide.

2. Step 2: The mechanism. - In this reaction, phenol reacts with chloroform in the presence of sodium hydroxide to form an intermediate dichlorocarbene, which then reacts with the phenol to form the salicylaldehyde. Thus, the reaction is known as the Reimer-Tiemann reaction.